A lawsuit called King v. Burwell would take health insurance away from millions of Americans, returning them to the world that existed before Obamacare. The case relies on a few words of the law that, if read out of context, seem to deny tax credits intended to help people pay for their health insurance to people who live in the wrong states. Once those words are read in the context of the entire law, however, it becomes clear that tax credits are available in all 50 states.

A brief filed on behalf of multiple public health scholars and the American Public Health Association, estimates that “over 9,800 additional Americans” will die if the justices side with the King plaintiffs. It reaches this conclusion by starting with an Urban Institute study showing that 8.2 million people will become uninsured in this scenario. As other research examining Obamacare-like reforms in the state of Massachusetts found that “for every 830 adults gaining insurance coverage there was one fewer death per year,” that translates to between 9,800 and 9,900 deaths if the justices back the plaintiffs in King.

Another method produces slightly less grim numbers, although it still indicates that thousands will die unnecessarily if the Supreme Court does not uphold the tax credits at issue in King. The Harvard study mentioned above concludes that there were “approximately 44,789 deaths among Americans aged 18 to 64 years in 2005 associated with lack of health insurance.” It also states that, at the time of the study, “46 million Americans lack health coverage.” The 8.2 million people who will lose health care according to the Urban Institute equals just under 18 percent of 46 million. Thus, assuming that the pool of 8.2 million people who could lose health insurance in King has a similar mix of healthy and sick individuals as the 46 million examined by the Harvard study, that suggests that approximately 8,000 people will die every year if the King plaintiffs prevail.

It should be noted, however, that two additional factors add uncertainty to the question of how many thousand of Americans will die if the Supreme Court rules against Obamacare in King. The first is that, even under the plaintiffs’ theory, if the Supreme Court cuts off tax credits in a state, the state government itself can restore those credits by setting up a state-run health exchange. Nevertheless, it is likely that many state leaders will prefer to allow their residents to lose health care before they do anything to aid Obamacare. After the Supreme Court made the law’s Medicaid expansion optional, 22 states have opted out of the expansion as of this writing. As similar number could choose not mitigate the damage the justices could cause in King.

The other factor is that approximately 8.4 million children are enrolled in the Children’s Health Insurance Program (CHIP), and the justices could take insurance away from 5 million of these children as well in King. That’s because a provision ensuring that CHIP beneficiaries remain insured even if Congress failed to extend CHIP funding beyond this September uses very similar language to the language at issue in King. So if the justices decide to cut off tax credits, they are likely to cut off CHIP funds as well for millions of children unless Congress intervenes by the deadline.

That means that, should the justices side with the King plaintiffs, the fate of 5 million children rests with a Republican-controlled Congress.

Children, by virtue of their youth, are less likely to have life-threatening health conditions than adults, so it is difficult to estimate how many children will die if the justices take away their health care — at least based on studies examining morality among adults. In any event, however, should the justices vote against Obamacare in King, the cost in human life is likely to include thousands of adult lives every year, in addition to the cost in children’s lives.